The first-year Republican governor signed the bill during a private ceremony in his Capitol office Wednesday.

Lawmakers passed the bill Tuesday during a special session on abortion called by Greitens.

Greitens has said he was motivated by a federal judge's ruling that struck down some state abortion regulations. He says the special session also was in response to a St. Louis ordinance that bans discrimination based on reproductive health choices such as abortion.

The final bill appears to address Greitens' concerns. Supporters said it will exempt pregnancy care centers from the St. Louis ordinance. It also will impose a number of new regulations on the procedure, including mandatory annual inspections of clinics by the health department.